1. Field of the Invention
This invention concerns synthetic sweeteners. More particularly, it concerns a new group of substituted dihydrochalcone compounds, their use as sweeteners for edible compositions such as foodstuffs, and certain amino dihydrochalcone intermediates.
2. Description of the Prior Art
Dihydrochalcones are compounds having a ##STR3## basic structure. A number of such compounds, both natural and synthetic, have been disclosed in the prior art. These materials vary from one another by the nature and placement of substituents on the aromatic rings.
In 1963, dihydrochalcones took an increased importance when it was discovered that some, but by no means all, of their number are sweet (Horowitz and Gentili, U.S. Pat. No. 2,087,871, issued Apr. 30, 1963). The earliest examples of sweet dihydrochalcones were derived from naturally occurring materials (flavanones) having saccharide residues attached at position four. More recently, applicants, their coworkers, and others have disclosed several sweet dihydrochalcones having smaller and simpler substituents at their four positions as evidenced by: Rizzi, U.S. Pat. No. 3,855,301, issued Dec. 17, 1974; Rizzi, U.S. Pat. No. 3,751,270, issued Aug. 7, 1973; Ibaraki, et al., U.S. Pat. No. 3,828,030, issued Aug. 6, 1974; Farkus et al., U.S. Pat. No. 3,956,375, issued May 11, 1976; Crosby et al., U.S. Pat. No. 3,974,299, issued Aug. 10, 1976; Crosby et al., U.S. Pat. No. 4,055,678, issued Oct. 25, 1977; DuBois et al., U.S. Pat. No. 4,336,804, issued Oct. 1, 1980; as well as pending United States patent application Ser. No. 19,054, which shows dihydrochalcones having an amino acid type structure at their 4 position.
This work has repeatedly confirmed the empirical nature of the taste-chemical structure relationship. The exact nature of substituents and their placement on the molecule are critical. A change which is minor on its face may have a major effect on the taste properties of the dihydrochalcone. Two taste-related major goals of dihydrochalcone sweetener research are: (1) To provide compounds having solubility in aqueous media adequate to form suitably sweet consumer products; and (2) To eliminate, or at least minimize, the menthol-like aftertaste and prolonged sweet aftertastes which have plagued many of the dihydrochalcones prepared heretofore. The present invention seeks to realize these goals.